I've now owned Nikon's elaborately named "AF-S DX NIKKOR 16-85mm f/3.5-5.6G ED VR" lens for well over two years, and I'm incredibly happy with it. The excellent focal range makes it a superb walk-around lens. The 16mm wide-end is really something special on a "normal" range DX zoom, since most only go as wide as 18mm. Its superb sharpness when combined with those extra 2mm make for a very capable landscape lens. The brilliant optical stabilization system (Nikon's VR) makes getting hand-held low-light shots a breeze.

All of these characteristics make it an absolutely oustanding lens, especially for casual travelers. Photographing the interior of a dimly-lit cathedral? No problem: the 16mm wide end and VR stabilization make it a breeze. Want to capture the some of the exterior architectural details? Again, no big deal: the 85mm long end and superb sharpness can make it happen.

These features all add up to mean that it has been my primary travel and walk-around lens ever since I purchased it back in 2009. Many of the most viewed images in my portfolio have been taken with it:

Underground RailBoston Celtics

Waiting for the Red Line

Harry Elkins Widener

So, what is there to complain about? Not much, but I've always wanted something that's a bit faster. Constant fast-aperture "normal" zoom lenses are great for subject isolation at events like weddings, and their focal length coverage means that they're also handy all sorts of other things (including landscapes). They can also make for excellent travel lenses. One can easily go from shooting serene landscapes (stopped-down a bit at the wide-end), to beautiful portraits (wide-open at the long end) without having to swap lenses.

Nikon makes a well-reviewed 17-55mm f/2.8 zoom, but it lacks VR stabilization and is quite expensive (around $1500 at the time of this article's publication). Fortuantely, Sigma has recently released the stabilized "17-50mm f/2.8 EX DC OS HSM". At $670, it's comparatively priced to Nikon's 16-85 VR which sells for $650. The Sigma gives up 1mm on the wide end and 35mm on the long end, but makes up for it with an f/2.8 constant fast aperture. It's also worth noting that the Sigma has a more common 77mm filter thread, while the Nikon 16-85 uses 67mm filters.

Photozone.de has excellent technical reviews of both of these lenses. You can compare the resolution, distortion, abberations, bokeh, and other factors at the links below:

On paper the 16-85 VR is a bit sharper than the 17-50 OS when stopped down to their sharpest settings (f/8.0 and f/5.6, respectively). The 17-50 is actually quite sharp in the center when wide-open, which is great news for the casual portrait photographer. But the real question is, how do they stack up against each other, image-for-image? Let's find out.

Field of View

Below are some GIF images which compare the lenses at their different settings.

16-85 vs. 17-50 @ widest focal lengths

16-85 vs. 17-50 @ widest focal lengths

16-85 vs. 17-50 @ longest focal lengths (and 50mm)

As you can see, the 16-85 VR has a significantly wider field-of-view than the 17-50 OS. The difference is so large, in fact, that I believe the focal length of the Sigma is more like 18mm. That's quite disappointing. Of course, it also has significantly less reach on the long end, but that's expected. The Nikon most certainly wins here.

Sharpness

Time for some 100% crops. Center first, at their widest focal lengths and sharpest apertures.

16-85 VR @ 16mm, f/8.0 (center crop)17-50 OS @ 17mm, f/5.6 (center crop)The 17-50 is most certainly sharper in the center at 17mm. What about at the extreme edges?

16-85 VR @ 16mm, f/8.0 (corner crop)17-50 OS @ 17mm, f/5.6 (corner crop)The Sigma loses this battle. But what if we stop it down to f/8.0?

17-50 OS @ 17mm, f/8.0 (corner crop)

Getting better... but still not as good as the Nikon. At 50mm these lenses look virtually identical in the center. However, again, the Sigma loses sharpness in the very extreme corners. It's worth noting that only the most extreme corners are problematic with the Sigma. The non-corner edges look quite good, and the average sharpness across the frame is outstanding.

Verdict? This one is a draw. It comes down to this: do you prefer the Nikon's overall sharpness consistency over the Sigma's slightly sharper center and slightly worse extreme corners?

Aperture

One advantage that the 17-50 OS does have, however is the f/2.8 constant aperture. This can make for some pretty decent portraits at (or around) 50mm.

17-50 OS @ 45mm, f/2.8

The above photo is cropped a bit. If I had been standing a bit closer and had framed it properly, the background would look much more bokeh-licious (more blurry). Here's a 100% crop:

17-50 OS @ 45mm, f/2.8 (center crop)

Sharp, and very nice. For comparison, I took this portrait a few years ago right after I got my 16-85 VR:

16-85 VR @ 85mm, f/5.6Also very sharp, and actually it's quite good. I had to stand further back and ended up with a tighter framing since I was shooting at 85mm. Both lenses do well here, but I'll give the edge to the Sigma since it has the faster aperture and a creamier look. I wish I had time during this review to take some better portraits. I may update this section in the future if I come up with anything better.

Conclusions

I want to love the 17-50 OS, but it just leaves a bit too much to be desired. Yes, the f/2.8 aperture opens up some great portrait options when used as a casual walk-around lens. The major downside for me is that the 17mm wide end is just too restrictive when compared to the 16-85 VR. That extra little bit makes a huge difference. The Sigma also has a few funny quirks: the zoom ring turns the "wrong" way compared to Nikon lenses, which is rather annoying. The OS works well, but seems to consume battery at a slightly faster rate than the 16-85 VR.

Sigma 17-50 f/2.8 OS PROS

fast aperture (excellent in low-light)

good construction (on par with the Nikon)

excellent sharpness stopped-down (except the extreme corners)

excellent center sharpness wide-open

OS works well

standard 77mm filter size

Sigma 17-50 f/2.8 OS CONS

wider would be better (17mm seems more like 18mm)

zoom action turns in the wrong direction (for Nikon users, it's hard to get used to)

no weather-sealing (missing the butt-gasket, too)

larger and heavier than the Nikon

focus ring turns in AF mode (make sure those fingers are out of the way!)

Nikon 16-85 VR PROS

excellent focal length range (16mm is wide)

good construction

excellent overall sharpness, especially in the corners

VR works well

lighter and smaller than the Sigma

Nikon 16-85 VR CONS

slow aperture, especially at maximum zoom (bad in low-light)

non-standard 67mm filter size

no weather-sealing (although it has a butt-gasket to keep moisture from the lens mount area)

What do I really want in a fast-aperture DX "normal" zoom? A 16mm wide-end is a must. Excellent sharpness across the frame is a must as well. Finally, either a slightly longer-than-normal focal length (70mm on the long end) with a moderately fast aperture, or a very fast aperture and a shorter focal length (f/2 and 40mm).

For me, and I suspect for many others, either of these imaginary specs would be perfect:

16-70 f/3.5 (stabilized)

16-40 f/2 (stabilized)

If this rumor has any truth to it, we all may be in luck... but for now I'll probably stick with the 16-85 VR.

Reader Comments (3)

Beautiful photos Michael. And thank you for the comparison. It was a pleasure to read. I have been wondering about these two lenses, having read so many different opinions about them. Photo comparison always helps!

This article is helpful. I really hesitate between those 2 lens, I know they design for different purpose. But I think I should stop dreaming of a large aperture VR walking around lens, choosing 16-85 VR seems to be a practical choice.

Thanks. This posting was so helpful that I made up my mind. 16-85 seems a good choice if it would be used under sunlight. But 17-50 will be a better choice if users mainly want to take a picture in a confined room space. In 17-50, it is understood that soft edge can be seen only at 'edge'. We need to notice that main object is usually located around center and background is out of focusing, meaning soft edge is not so important. But it seems better to increase F value when we take a scenery view to obtain sharp edge.